The present invention relates to a semiconductor device, and is a technology, for example, applicable to a power device.
As an electronic element that controls a high voltage and a large current, presently, a power device is used. As one of power devices, there is an LDMOS (Laterally Diffused Metal Oxide Semiconductor). In the LDMOS, generally, a gate electrode and a drain region are spaced apart from each other in plan view. Further, a field insulating film is formed between the gate electrode and the drain region.
Further, presently, as the structure of the LDMOS, structures described in US Patent Application Publication No. 2012/0043608 (Patent document 1) or J. Jang, K.-H. Cho, D. Jang, M. Kim, C. Yoon, J. Park, H. Oh, C. Kim, H. Ko, K. Lee and S. Yi, “Interdigitated LDMOS”, ISPSD 2013 The 25th International Symposium on Power Semiconductor Devices and ICs, LV-P8 (Non-Patent document 1) are proposed. In Patent document 1 and Non-Patent document 1, field insulating films formed on the side face of the drain region in a comb-tooth-shape in plan view project from the drain region side toward the gate electrode side. Furthermore, the LDMOS described in Non-Patent document 1 has a plurality of projection parts projecting from the side face of the gate electrode from the source region side toward the drain region side. Each of the projection parts is provided corresponding to each of a plurality of comb teeth of the field insulating film, and at least a part of each of the projection parts lies over each of the field insulating films.